1. Carefully trim all the fat and the cartilage from the chicken breasts, using a sharp knife or kitchen scissors.
2. To make the marinade, place all ingredients in a shallow dish, large enough to hold the chicken in a single layer. Mix the ingredients gently until combined.
3. Add chicken to marinade, and coat well. Cover and marinate in refrigerator for at least 1 hour, turning after 30 minutes.
4. Prepare a medium-hot barbecue, or preheat a grill to high. Spray barbecue rack or grill rack with vegetable oil.
5. Remove chicken from the marinade and barbecue or grill for 5 minutes, brushing frequently with the marinade. Turn the chicken and cook for a further 10 to 15 minutes, or until cooked, brushing frequently with the marinade. Test the chicken with a skewer: the juices should be clear when the chicken is cooked.